Heat exchanger

ABSTRACT

A heat exchanger includes a mounting section on which heat-exchanged object is mounted, and a circulation section in which a plurality of flow paths through which a heating medium flows are formed, wherein the plurality of flow paths include first flow paths in which a flow path width in a third direction vary according to advance in a first direction at a side closer to a first end portion and at a side closer to a second end portion of the first flow path in a second direction, the flow path width of the first flow path at the side closer to the first end portion varies with a decrease tendency according to advance in the first direction, and the flow path width of the first flow path at the side closer to the second end portion varies with an increase tendency according to advance in the first direction.

CROSS-REFERENCE TO RELATED APPLICATION

Priority is claimed on Japanese Patent Application No. 2018-134917,filed Jul. 18, 2018, the content of which is incorporated herein byreference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a heat exchanger.

Description of Related Art

In the related art, a heat exchanger including fins for heat transfer ina coolant flow path is known (for example, see Japanese UnexaminedPatent Application, First Publication No. H04-018232 and Japanese PatentNo. 5387436). The fins for a heat exchanger are formed of a plate-shapedmember provided parallel to a flow direction of a coolant. In thesefins, a shape of a cross section perpendicular to the flow direction ofthe coolant is a rectangular waved shape. These fins are so-calledoffset fins, and neighboring waved-shaped portions in the flow directionof the coolant are offset in a direction perpendicular to the flowdirection of the coolant.

SUMMARY OF THE INVENTION

Incidentally, in the above-mentioned heat exchanger, since the coolantflows in a direction parallel to a plate-shaped member that forms thefins, movement of the coolant in a height direction of the fins isminimized. For this reason, when a radiating surface with respect to aheat source (i.e., an object to be heat-exchanged) is provided on endportions (for example, base end portions or tip portions) of the fins inthe height direction, a temperature of the coolant flowing close to theradiating surface is easily maintained relatively high, and atemperature of the coolant flowing far side from the radiating surfaceis easily maintained relatively low. When a state in which a temperaturedifference is large is maintained without promoting homogenization of atemperature distribution of the coolant depending on a position in theflow path in this way, a problem that heat exchange effectiveness cannotbe improved occurs.

An aspect of the present invention is directed to providing a heatexchanger capable of promoting efficient heat exchange.

The present invention employs the following aspects.

(1) A heat exchanger according to an aspect of the present inventionincludes a mounting section on which an object to be heat-exchanged ismounted; and a circulation section in which a plurality of flow pathsthrough which a heating medium flows are formed, wherein, provided thata first direction is a flow direction of the heating medium, a seconddirection is perpendicular to the mounting section and a third directionis perpendicular to the first and second directions, the plurality offlow paths include first flow paths in which a flow path width in thethird direction vary according to advance in the first direction at aside closer to a first end portion of the first flow path in the seconddirection and at a side closer to a second end portion of the first flowpath in the second direction, the flow path width of the first flow pathat the side closer to the first end portion varies with a decreasetendency according to advance in the first direction, and the flow pathwidth of the first flow path at the side closer to the second endportion varies with an increase tendency according to advance in thefirst direction.

(2) In the heat exchanger according to the above-mentioned (1), theplurality of flow paths may include second flow paths which are disposednext to the first flow paths in the third direction and in which flowpath widths in the third direction vary according to advance in thefirst direction at a side closer to the first end portion of the firstflow path in the second direction and at a side closer to the second endportion of the first flow path in the second direction, the flow pathwidth of the second flow path at the side closer to the first endportion may vary with an increase tendency according to advance in thefirst direction, and the flow path width of the second flow path at theside closer to the second end portion may vary with a decrease tendencyaccording to advance in the first direction.

(3) In the heat exchanger according to the above-mentioned (1) or (2), across-sectional area on an upstream side and a cross-sectional area on adownstream side in the first direction at each of the plurality of flowpaths may be formed to be the same as each other.

(4) In the heat exchanger according to any one of the above-mentioned(1) to (3), the circulation section may include a plurality of flow pathrows disposed to be arranged in the first direction, each of theplurality of flow path rows may be configured such that the plurality offlow paths are disposed to be arranged in the third direction, and,among the plurality of flow path rows, an upstream-side flow path and adownstream-side flow path next to each other may be disposed to beshifted in the third direction.

(5) In the heat exchanger according to the above-mentioned (4), amongthe plurality of flow path rows, the upstream-side flow path and thedownstream-side flow path that are next to each other may be disposedsuch that at least parts thereof are integrally connected with eachother while being shifted at 1/N pitch in the third direction by anarbitrary natural number N larger than 1.

According to the above-mentioned (1), the heating medium flowing throughthe first flow path in the first direction is guided to flow from thefirst end portion side toward the second end portion in the seconddirection according to a decrease in the flow path width at the sidecloser to the first end portion in the second direction and an increasein the flow path width at the side closer to the second end portion inthe second direction. Accordingly, the heating medium flowing through aside close to the object to be heat-exchanged and the heating mediumflowing through a side far from the object to be heat-exchanged can bestirred so as to be mixed. Even in a case a temperature difference isincreased in a state in which there is no mixing between the heatingmedium flowing through the side close to the object to be heat-exchangedand the heating medium flowing through the side far from the object tobe heat-exchanged, efficient heat exchange can be performed by stirringthe heating medium and promoting uniformization of the temperaturedistribution.

In the case of the above-mentioned (2), in the second flow path next tothe first flow path, the heating medium can be stirred by an actionopposite to that of the first flow path. That is, the heating mediumflowing through the second flow path in the first direction is guided toflow from the second end portion side toward the first end portion inthe second direction according to the increase in flow path width at theside closer to the first end portion of the first flow path in thesecond direction and the decrease in the flow path width at the sidecloser to the second end portion of the first flow path in the seconddirection. Accordingly, the heating medium flowing through the sideclose to the object to be heat-exchanged and the heating medium flowingthrough the side far from the object to be heat-exchanged can be stirredso as to be mixed.

Further uniformization of the temperature distribution can be furtherpromoted and heat exchange efficiency can be improved by stirring theheating media using actions reverse to each other in the first flow pathand the second flow path.

In the case of the above-mentioned (3), since the constantcross-sectional area of the flow path in the flow direction of theheating medium is formed, occurrence of an excessive pressure increaseor pressure drop in a part of the flow path can be minimized.

In the case of the above-mentioned (4), in comparison with the case inwhich the upstream-side flow path and the downstream-side flow pathhaving the same shape are not shifted in the third direction, heatexchange efficiency can be improved.

In the case of the above-mentioned (5), the plurality of flow paths canbe formed by pressing, for example, cutting and bending or the like, ofone plate member, the plurality of flow paths can be formed to beintegrally connected to each other without being separated from eachother, and manufacturing efficiency can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view schematically showing aconfiguration of a heat exchanger according to an embodiment of thepresent invention.

FIG. 2 is a perspective view showing a flow path forming member of aheat exchanger according to the embodiment of the present invention.

FIG. 3 is an enlarged perspective view showing a part of a flow pathforming member of the heat exchanger according to the embodiment of thepresent invention.

FIG. 4 is a perspective view showing the flow path forming member of theheat exchanger according to the embodiment of the present invention in adirection inclined with respect to a Z-axis direction.

FIG. 5 is a view showing the flow path forming member of the heatexchanger according to the embodiment of the present invention in aY-axis direction.

FIG. 6 is a view showing the flow path forming member of the heatexchanger according to the embodiment of the present invention in aZ-axis direction.

FIG. 7A is a cross-sectional view taken along an X-Z plane at a positionon line A-A shown in FIG. 6.

FIG. 7B is a cross-sectional view taken along the X-Z plane at aposition on line B-B shown in FIG. 6.

FIG. 7C is a cross-sectional view taken along the X-Z plane at aposition on line C-C shown in FIG. 6.

FIG. 7D is a cross-sectional view taken along the X-Z plane at aposition on line D-D shown in FIG. 6.

FIG. 7E is a cross-sectional view taken along the X-Z plane at aposition on line E-E shown in FIG. 6.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, an embodiment of a heat exchanger of the present inventionwill be described with reference to the accompanying drawings.

FIG. 1 is an exploded perspective view schematically showing aconfiguration of a heat exchanger 10 according to the embodiment of thepresent invention. FIG. 2 is a perspective view showing a flow pathforming member 21 of the heat exchanger 10 according to the embodimentof the present invention. FIG. 3 is an enlarged perspective view showinga part of the flow path forming member 21 of the heat exchanger 10according to the embodiment of the present invention. FIG. 4 is aperspective view showing the flow path forming member 21 of the heatexchanger 10 according to the embodiment of the present invention in adirection inclined with respect to a Z-axis direction. FIG. 5 is a viewshowing the flow path forming member 21 of the heat exchanger 10according to the embodiment of the present invention in a Y-axisdirection. FIG. 6 is a view showing the flow path forming member 21 ofthe heat exchanger 10 according to the embodiment of the presentinvention in a Z-axis direction. FIG. 7A to FIG. 7E are cross-sectionalviews taken along an X-Z plane at positions on lines A-A, B-B, C-C, D-D,and E-E shown in FIG. 6. Further, hereinafter, axial directions of an Xaxis, a Y axis and a Z axis that are perpendicular to each other in a3-dimensional space are directions parallel to the axes.

As shown in FIG. 1, the heat exchanger 10 includes a heat radiation case11, and a heat radiation plate 13 mounted on the heat radiation case 11.

An external form of the heat radiation case 11 is, for example, arectangular box shape. The heat radiation plate 13 closes an opening endof the heat radiation case 11 to liquid-tightly seal the inside of theheat radiation case 11.

A supply port 13 a and a discharge port 13 b for a heating medium (forexample, a coolant) R are formed in the heat radiation plate 13. Thesupply port 13 a and the discharge port 13 b are formed in, for example,two non-adjacent corner sections among four corner sections of the heatradiation plate 13. The heating medium R entering the heat radiationcase 11 from the supply port 13 a flows through the heat radiation case11 and flows to the outside of the heat radiation case 11 from thedischarge port 13 b.

An outer surface of the heat radiation case 11 (for example, an outersurface of a bottom section 11 a) includes a mounting section (forexample, a mounting surface) 15 on which an object to be heat-exchanged(for example, a heat source) P is mounted. The heat radiation case 11includes a circulation section 19 in which a plurality of flow paths 17through which the heating medium R flows are formed.

For example, a thickness direction of the heat radiation case 11 is adirection perpendicular to the mounting section 15, and parallel to theZ-axis direction. A positive direction of the circulation section 19 inthe Z-axis direction is a direction getting away from the object to beheat-exchanged P on the mounting section 15. A flow direction of theheating medium R in the heat radiation case 11 is a direction parallelto the mounting section 15 and parallel to the Y-axis direction. Apositive direction of the circulation section 19 in the Y-axis directionis a direction along a flow direction of the heating medium R. TheX-axis direction is perpendicular to the Z-axis direction and the Y-axisdirection.

As shown in FIG. 2, FIG. 3, FIG. 4 and FIG. 5, the circulation section19 includes the flow path forming member 21 that forms the plurality offlow paths 17. An external form of the flow path forming member 21 in across section (i.e., a Z-X plane) perpendicular to a flow direction ofthe heating medium R is, for example, a trapezoidal wave form. The flowpath forming member 21 is formed by pressing, for example, cutting andbending or the like, one plate member. The flow path forming member 21includes a first bottom section 23, a second bottom section 25, and afirst wall section 27 and a second wall section 29 configured to connectthe first bottom section 23 and the second bottom section 25.

External forms of the first bottom section 23 and the second bottomsection 25 are, for example, the same isosceles trapezoidal plateshapes. A symmetrical axis in an isosceles trapezoidal shape of thefirst bottom section 23 and the second bottom section 25 is parallel tothe Y-axis direction, i.e., the flow direction of the heating medium R.In the isosceles trapezoidal shape of the first bottom section 23 andthe second bottom section 25, an upper base on a downstream side in theflow direction of the heating medium R is formed to be shorter than alower base on an upstream side in the flow direction of the heatingmedium R. That is, a width of each of the first bottom section 23 andthe second bottom section 25 in the X-axis direction varies with adecrease tendency according to advance in a positive direction of theY-axis direction in the flow direction of the heating medium R.

An external form of the first wall section 27 and the second wallsection 29 is formed in, for example, a plate shape in which each ofthem is connected to mutual legs in the isosceles trapezoidal shape ofthe first bottom section 23 and the second bottom section 25.

The plurality of flow paths 17 include a plurality of first flow paths31 and second flow paths 32.

The first flow paths 31 are formed by the first bottom section 23, thefirst wall section 27, the second wall section 29, and the bottomsection 11 a of the heat radiation case 11. As shown in FIG. 6 and FIG.7A to FIG. 7E, a flow path width of the first flow paths 31 in theX-axis direction on a side in the positive direction of the Z-axisdirection, i.e., on the side closer to first end portions 31 a, varieswith a decrease tendency according to advance in the positive directionof the Y-axis direction in the flow direction of the heating medium R. Aflow path width of the first flow paths 31 in the X-axis direction on aside in the negative direction of the Z-axis direction, i.e., on theside closer to second end portions 31 b, varies with an increasetendency according to advance in the positive direction of the Y-axisdirection in the flow direction of the heating medium R.

For example, flow path widths W1 a 1, W1 a 2, W1 a 3, W1 a 4 and W1 a 5on the side closer to the first end portions 31 a that vary according toadvance in the positive direction of the Y-axis direction have arelation of W1 a 1>W1 a 2>W1 a 3>W1 a 4>W1 a 5. Flow path widths W1 b 1,W1 b 2, W1 b 3, W1 b 4 and W1 b 5 on the side closer to the second endportions 31 b that vary according to advance in the positive directionof the Y-axis direction have a relation of W1 b 1<W1 b 2<W1 b 3<W1 b4<W1 b 5.

As shown in FIG. 2 and FIG. 3, the heating medium R flowing through thefirst flow paths 31 in the positive direction of the Y-axis direction isguided to flow from the first end portions 31 a side toward the secondend portions 31 b side according to a decrease in the flow path width onthe side closer to the first end portions 31 a and an increase in theflow path width on the side closer to the second end portions 31 b.

The second flow paths 32 are formed by the second bottom section 25, thefirst wall section 27, the second wall section 29, and the heatradiation plate 13. As shown in FIG. 6 and FIG. 7A to FIG. 7E, a flowpath width of the second flow paths 32 in the X-axis direction on theside in the positive direction of Z-axis direction, i.e., on the sidecloser to first end portions 32 a, varies with an increase tendencyaccording to advance in the positive direction of the Y-axis directionin the flow direction of the heating medium R. A flow path width of thesecond flow paths 32 in the X-axis direction on the side in the negativedirection of the Z-axis direction, i.e., on the side closer to secondend portions 32 b, varies with a decrease tendency according to advancein the positive direction of the Y-axis direction in the flow directionof the heating medium R.

For example, flow path widths W2 a 1, W2 a 2, W2 a 3, W2 a 4 and W2 a 5on the side closer to the first end portions 32 a that vary according toadvance in the positive direction of the Y-axis direction have arelation of W2 a 1<W2 a 2<W2 a 3<W2 a 4<W2 a 5. Flow path widths W2 b 1,W2 b 2, W2 b 3, W2 b 4 and W2 b 5 on the side closer to the second endportions 32 b that vary according to advance in the positive directionof the Y-axis direction have a relation of W2 b 1>W2 b 2>W2 b 3>W2 b4>W2 b 5.

As shown in FIG. 2 and FIG. 3, the heating medium R flowing through thesecond flow paths 32 in the positive direction of the Y-axis directionis guided to flow from the second end portions 32 b side toward thefirst end portions 32 a side according to an increase in the flow pathwidth on the side closer to the first end portions 32 a and a decreasein the flow path width on the side closer to the second end portions 32b.

In each of the first flow paths 31 and the second flow paths 32, across-sectional area in the Y-axis direction is formed to be constantwithin a predetermined error range. That is, in each of the first flowpaths 31 and the second flow paths 32, a cross-sectional area on anupstream side and a cross-sectional area on a downstream side in theY-axis direction along the flow direction of the heating medium R areformed to be the same within the predetermined error range.

As shown in FIG. 4 and FIG. 5, the plurality of first flow paths 31 andthe plurality of second flow paths 32 are disposed in, for example, azigzag manner. In the X-axis direction, the plurality of first flowpaths 31 and the plurality of second flow paths 32 are alternatelyarranged and integrally next to each other. In the Y-axis direction, theplurality of first flow paths 31 are arranged to be sequentially shiftedin the X-axis direction, and the plurality of second flow paths 32 arearranged to be sequentially shifted in the X-axis direction.

For example, the circulation section 19 includes a plurality of flowpath rows 40 disposed integrally to be arranged in the Y-axis direction.Each of the flow path rows 40 is configured to be disposed integrallysuch that the plurality of first flow paths 31 and the plurality ofsecond flow paths 32 are alternately arranged in the X-axis direction.Among the plurality of flow path rows 40, the flow path row 40 on theupstream side and the flow path row 40 on the downstream side, which arenext to each other, are disposed to be shifted in the X-axis direction.That is, in the plurality of flow path rows 40, the first flow path 31on the upstream side and the first flow path 31 on the downstream side,which are next to each other, are disposed to be shifted in the X-axisdirection, and the second flow path 32 on the upstream side and thesecond flow path 32 on the downstream side are disposed to be shifted inthe X-axis direction.

Two arbitrary first flow paths 31 arranged in the Y-axis direction andtwo arbitrary second flow paths 32 arranged in the Y-axis direction aredisposed to be shifted at 1/N pitch (=L/N) in the X-axis direction.Further, 1 pitch is a distance L between the two first flow paths 31neighboring in the X-axis direction or a distance L between the twosecond flow paths 32 neighboring in the X-axis direction. In addition, Nis an arbitrary natural number larger than 1, for example, N=4. The twoarbitrary first flow paths 31 and the two arbitrary second flow paths32, which are arranged in the Y-axis direction, are disposed such thatat least parts thereof are integrally connected to each other.

That is, the flow path forming member 21 forms a so-called offset fin.In the offset fin, for example, one flow path group is formed by theplurality of first flow paths 31 and second flow paths 32 alternatelyarranged in the X-axis direction, and the plurality of flow path groupsare disposed to be arranged in the Y-axis direction while beingsequentially shifted at 1/N pitch in the X-axis direction.

As described above, according to the heat exchanger 10 of theembodiment, in the first flow paths 31 and the second flow paths 32, theheating medium R flowing in the positive direction of the Y-axisdirection is stirred in the Z-axis direction. Accordingly, the heatingmedium R flowing through a side close to the object to be heat-exchangedP and having a relatively high temperature and the heating medium Rflowing through a side far from the object to be heat-exchanged P andhaving a relatively low temperature are suppressed from becoming alaminar flow, and mixing thereof can be promoted. Efficient heatexchange can be performed by stirring the heating medium R having avariation in temperature that increases according to a distance from theobject to be heat-exchanged P and promoting uniformization of atemperature distribution of the heating medium R depending on positionsin the flow paths 31 and 32.

In addition, in each of the first flow paths 31 and the second flowpaths 32, since a cross-sectional area in the Y-axis direction along theflow direction of the heating medium R is formed to be constant,occurrence of an excessive pressure increase or pressure drop in partsof the flow paths 31 and 32 can be suppressed.

In addition, since the two arbitrary first flow paths 31 arranged in theY-axis direction and the two arbitrary second flow paths 32 arranged inthe Y-axis direction are disposed to be shifted at 1/N pitch in theX-axis direction, for example, heat exchange efficiency can be improvedin comparison with the case in which the paths are not shifted in theX-axis direction.

In addition, the flow path forming member 21 can form the plurality offlow paths 17 through pressing of one plate member, the plurality offlow paths 17 can be formed to be integrally connected without beingseparated, manufacturing efficiency can be improved, and an increase incost required for manufacturing of the compact heat exchanger 10 can beminimized.

Hereinafter, a variant of the embodiment will be described.

While the object to be heat-exchanged P is a heat source, i.e., acooling target, and the heating medium R is a coolant in theabove-mentioned embodiment, there is no limitation thereto. The objectto be heat-exchanged P may be a heating target or the heating medium Rmay be a heat medium.

In addition, while the circulation section 19 includes the plurality offlow path rows 40 disposed integrally to be arranged next to each otherin the Y-axis direction in the above-mentioned embodiment, there is nolimitation thereto. For example, in the plurality of flow path rows 40arranged in the Y-axis direction, a predetermined interval may beprovided between the neighboring flow path rows 40, and the neighboringflow path rows 40 may be separated from each other without beingintegrally connected to each other.

While preferred embodiments of the invention have been described andillustrated above, it should be understood that these are exemplary ofthe invention and are not to be considered as limiting. Additions,omissions, substitutions, and other modifications can be made withoutdeparting from the scope of the present invention. Accordingly, theinvention is not to be considered as being limited by the foregoingdescription, and is only limited by the scope of the appended claims.

What is claimed is:
 1. A heat exchanger comprising: a mounting section on which an object to be heat-exchanged is mounted; and a circulation section in which a plurality of flow paths through which a heating medium flows are formed, wherein, provided that a first direction is a flow direction of the heating medium, a second direction is perpendicular to the mounting section and a third direction is perpendicular to the first and second directions, the plurality of flow paths comprise first flow paths in which a flow path width in the third direction vary according to advance in the first direction at a side closer to a first end portion of the first flow path in the second direction and at a side closer to a second end portion of the first flow path in the second direction, the flow path width of the first flow path at the side closer to the first end portion varies with a decrease tendency according to advance in the first direction, and the flow path width of the first flow path at the side closer to the second end portion varies with an increase tendency according to advance in the first direction.
 2. The heat exchanger according to claim 1, wherein the plurality of flow paths comprise second flow paths which are disposed next to the first flow paths in the third direction and in which flow path widths in the third direction vary according to advance in the first direction at a side closer to the first end portion of the first flow path in the second direction and at a side closer to the second end portion of the first flow path in the second direction, the flow path width of the second flow path at the side closer to the first end portion varies with an increase tendency according to advance in the first direction, and the flow path width of the second flow path at the side closer to the second end portion varies with a decrease tendency according to advance in the first direction.
 3. The heat exchanger according to claim 1, wherein a cross-sectional area on an upstream side and a cross-sectional area on a downstream side in the first direction at each of the plurality of flow paths are formed to be the same as each other.
 4. The heat exchanger according to claim 1, wherein the circulation section comprises a plurality of flow path rows disposed to be arranged in the first direction, each of the plurality of flow path rows is configured such that the plurality of flow paths are disposed to be arranged in the third direction, and among the plurality of flow path rows, an upstream-side flow path and a downstream-side flow path next to each other are disposed to be shifted in the third direction.
 5. The heat exchanger according to claim 4, wherein, among the plurality of flow path rows, the upstream-side flow path and the downstream-side flow path that are next to each other are disposed such that at least parts thereof are integrally connected to each other while being shifted at 1/N pitch in the third direction by an arbitrary natural number N larger than
 1. 